The present invention is directed generally to centrifugal fluid separation devices and more particularly involves a pressure driven and/or balanced separation device preferably having a simplified disposable tubing and bag set used with a loopless, rotating sealless rotor.
A number of fluid separation devices have been known and various models are currently available for the separation of blood or other composite fluids into the various component elements thereof. For example, a variety of centrifugal machines are available for separating blood into component elements such as red blood cells, platelets and plasma, among others.
Centrifugation for such purposes has come in many forms in both continuous and batch types. For example, in the widely used process known as continuous centrifugation, as generally opposed to batch process centrifugation, a continuous input of a composite fluid is flowed into the separation device or chamber while at the same time the components of that composite fluid are substantially continuously separated and these separated components are usually then also substantially continuously removed therefrom. Many currently popular forms of such continuous fluid separation devices include loops of entry and exit flow tubing lines connected to the separation centrifuge chamber such that each loop is rotated in a relative one-omega—two-omega (1ω–2ω) relationship to the centrifuge chamber itself so that the tubing lines will remain free from twisting about themselves.
An alternative form of tubing line connection to a continuous centrifugal separation device is also available in the art which does not have such a loop, but which instead requires one or more rotating seals at the respective connections of the tubing lines to the centrifuge separation chamber, again to maintain the tubing lines free from twisting.
Batch-type centrifugation, on the other hand, usually involves separation of a composite fluid such as whole blood in a closed container, often a deformable bag, followed by a usually complicated process of automated and/or manual expression of one or more of the separated components out of the separation container or bag. A great deal of control, either automated, such as by optical interface detection, or by a diligent human operator watching a moving interface, is required with such previous batch-type processes. Indeed, various means and methods have been used in prior centrifugal separation devices, both continuous and batch, for driving fluid flow and maintaining desirable interface position control between the component elements being separated thereby. For example, as mentioned, various optical feedback methods and devices have been employed in the art. Various pumping and valving arrangements are also used in various of these and other arrangements. Alternative relatively automatic volume flow and density relationship interface controls have also been used; for example, in a continuous system by the disposition of control outlet ports in strategic locations relative to the separated component outlet ports. Nevertheless, many facets of these prior separation devices, though satisfactorily productive, may provide certain features which are less efficient than a desired optimum. For example, centrifugal separation devices using loops of tubing lines rotated in the above-described 1ω–2ω relationship with the centrifuge separation chamber require significant, usually substantially large drive mechanisms which thereby mandate that each such entire device then also be necessarily of a relatively large scale. Rotating seal devices, on the other hand, require intricate and often operationally problematic rotating seal structures. Still further, prior fluid drive and/or interface control systems have generally been either overly complex, as in the case of most of the optical control models, and/or automatic volume flow/density controls may not be entirely efficient in separation due to the usually inherent re-mixing of some quantities of the centrifugally separated components.
Hence, substantial desiderata remain to provide more highly efficient centrifugal separation devices in terms of increased efficiency fluid flow drive and separation interface controls; reduced rotor drive mechanization, quantity and/or scale; and/or reduced seal need and/or intricacy. It is toward any one or more of these or other goals as may be apparent throughout this specification that the present invention is directed.